1. Field of the Invention
The present invention relates to a waveguide structure including a waveguide section rotatable about its longitudinal axis by means of an electric motor arrangement. Such an arrangement includes rotor means fixedly mounted on the waveguide section so as to be rotatable with the section about the longitudinal axis of the same.
The invention also relates to a microwave polarizer using the microwave structure and to a variable power combiner using the polarizer.
2. Brief Description of the Prior Art
U.S. Pat. Nos. 3,215,957 (DANTZIG ET Al) issued on Nov. 2, 1965, and 3,569,870 (FOLDES) issued on Mar. 9, 1971, describe microwave polarizer devices including a waveguide section rotatable about its geometrical longitudinal axis. In both cases, a first gear is mounted on the waveguide section in a plane perpendicular to the longitudinal axis of the same. A second gear in meshed engagement with the first one is mounted on the shaft of an electric motor, whereby this electric motor can rotate the waveguide section through the first and second gears. Such a prior art design therefore uses two gears in meshed engagement with respect to each other to rotate the waveguide section, which results in a complex polarizer device. Moreover, in order to accurately position the waveguide section by means of the two gears, a complex feedback control of the electric motor is provided (see U.S. Pat. No. 3,215,957).